Lock



E. N. .mcolsll 2,311,215

Loox v Filed oct. le, 1937 Patented Maf. 15, 193s UNITED sri* PATENTGFFICE VBriggs & Stratton Corporation, Milwaukee,

Wis., a corporation of Delaware Application October 16, 1937, Serial No.169,405

8 claims.

This invention relates to improvements in locks and refers particularlyto pin tumbler locks.

As disclosed in a copending application, Serial No. 141,713, filed May10th, 1937, in some types of pin tumbler locks the cylinder is:assembled with the casing from the rear. This necessitates the provisionof means to protect or guard the joint between the cylinder and itscasing at its exposed front end toprevent the insertion of a thin feelerbetween the cylinder and the wall of the bore for the purpose of pickingthe lock.

The present invention is directed generally to this type of lock and hasparticular reference` to a specic application of this lock ywherein theconstruction is such that the outside diameter of the cap or othercovering means used to protect the front end of the lock may not belarger than the diameter of the cylinder.

Another requirement of this specic; installation is that the key-Way beopen to the bore of the casing so that the key will rest on the bore ofthe casing and receive support therefrom.

This invention therefore contemplates as one of its objects to providean improved cap construction which meets these requirements in a simpleand practical manner.

Inasmuch as the main body of the cap may not be larger than the diameterof the cylinder,

and as the keyway must break through this portion of the cap as well asthe cylinder, it follows that the cap is necessarily weakened by its keyopening, and to guard against bursting or tearing the cap durin-g itsapplication to the cylinder, the invention has as a further object toprovide a novel connection between the cap and the cylinder. I

Another object of this invention is to provide a novel manner ofsecuring the cap in assembled relation with the cylinder and casing forinsertion into the support. y f

With the above and other objects in view which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement o-f parts substantially p as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims.

complete example of the physical embodiment of the invention constructedin accordance with the best mode so far devised for the practicalapplication of the principles thereof, and in which:

Figure 1 is a side view of the front end portion The accompanyingdrawing illustrates one- (Cl. 'Y0-450) of a lock embodying thisinvention, having parts broken away and in section;

Figure 2 is a front view of the lock, with parts broken away and insection on the plane of the line 2 2 of Figure 1;

Figure 3 is a bottom View of the cylinder and cap, showing the sameproperly assembled;

Figure 4 is a perspective view of the cap and cylinder shown separatedand ready for assembly; and

Figure 5 is a View partly in section and partly in elevation,illustrating the cap in the act of being applied to the cylinder.

Referring now particularly to the accompanying drawing in which likenumerals indicate like parts, the numeral 5 designates the casing of thelock which is adapted to be mounted in a support and which is bored asat 'I to rotatably receive a lock cylinder 8. The support 6 has achamber S to receive the casing and a hole in its front face into whichthe front end of the lock cylinder projects to lie substantially flushwith the front face of the support.

The cylinder is inserted into the casing bore 'I from its rear end andymeans (not shown) are provided to hold the cylinder against endwisedisplacement. The customary tumblers (not shown) are carried by thecylinder to be actuatable by a key insertable into a keway II whichopens directly to the outside surface of thevcylinderso that the bottomof the key rests on the bore of the casing.

The extreme front end I2 of the cylinder is reduced in diameter, and asheet metal cap I3 is telescopedfthereover. The diameter of the frontend portion I2 of the cylinder plus the metal thickness of the side wallI4 of the cap is substantially equal to the diameter of the cylinder soas to t the opening I9 in the support, in the same manner as an uncappedcylinder so that the capped construction is interchangeable withcylinders which are directly plated and nished and do not have separatecaps.

At a point in line with the shoulder I5 formed by the juncture of thebore or hole I!! with the cavity 9, the side wall of the cap is abruptlyenlarged in diameter, as is also the adjacent portion I6 of thecylinder. The extreme inner peripheral edge of the cap is flangedoutwardly, as at I'I, which ange is received in a counterbore I8 at themouth of the bore L` The abrupt enlargement of the cap diameter behindthe yshoulder I5 closes the space between the cylindrical surface of thecylinder and the wall of the casing bore to preclude the insertion ofthin feelers for the purpose of picking the lock.

Thecap is held in place on the cylinder by a tang i9 forming part of atumbler retainer 20 iitted to the casing. The tang I9 extends downintothe counterbore, as shown, to overlie the flange` l1.

A keyhole 2l is formed in the front Wall of the cap, which, to permitthe key to engage the wall of the bore 1 in the casing, extends throughthe small diameter forepart of the cap, as best shown in Figures 3 and4. This keyhole thus substantially splits the cap in two and to guardagainst bursting stresses incident to the application of the cap ontothe front end of the cylinder tearing the cap at the bottom of thekeyhole, two tangs 22 are provided in the side wall I4 of the cap, oneat each side of the keyhole.V These tangs project inwardly and engage inrecesses 23 in the adjacent forepart of the cylinder.

The side walls 24 of these recesses are inclined with respect to trueradial planes so that their inner ends at the bottoms of the recesseslie closer to the keyway than their outer ends. The circumferentialdistance around the front end of the cylinder from edge to edge of theside walls 24 thus increases slightly as this measurement progressestoward the bottoms of the recesses, consequently during the applicationof the cap to the front end of the cylinder, Vthe cap will be drawnabout the cylinder and the tendency to burst the cap will be offset. Itis also evident that the interengagernent of the tangs 22 and recesses23 secures the cap against rotation on the cylinder.

From the foregoing description taken in connection with the accompanyingdrawing, it will be readily apparent to those skilled in the art, thatthis invention provides a simple cap structure for cylinder locks, andthat it is particularly well suited to the requirements of aninstallation where the diameter of the forepart of the cap must be keptwithin that of the cylinder.

What I claim as my invention is:

1. In a lock, a bored casing, a lock cylinder rotatable therein, saidcylinder Ybeing inserted through the rear end of the bore and having itsfront end projecting fromthe casing and having a key slot opening in itscylindrical surface; a cap comprising front and side walls fitted to thefront end of the cylinder and having an outside diameter at its forepartsubstantially equal to the diameter of the cylinder, said cap having akeyhole in its front-wall continuing into the y side wall of itsforepart; and means for retaining the cap assembled with the cylinderincluding interengaging abutments on the cylinder and the side wall ofthe' cap at opposite sides of its keyhole.

2. In a lock, a bored casing, a lock cylinder rotatable therein, saidcylinder being inserted through the rear end of the bore and having itsfront end projecting from the casing and having a key slot opening inits cylindrical surface;

:.f a cap comprising front and side Walls tted to the front end ofthecylinder and having an outside'diameter at its forepart substantiallyequal to the diameter of the cylinder, said cap having a keyhole in itsfront wall continuing into the side wall of its forepart; and means forretaining the cap assembled with the cylinder including interenga-gingabutments on the cylinder and the side wall of the cap at opposite sidesof its keyhole, the abutments on at least one of said parts beingtapered so that during application of the cap to the cylinder, the capis drawn about the cylinder toward the key slot to offset burstingstresses incidental to the application of the cap to the cylinder.

3. In a lock, a lock cylinder having a key slot opening to thecylindrical surface thereof; a cap tted over the iront end of thecylinder, said cap having a front wall provided with a keyhole and acylindrical side wall telescoped over the forepart of the cylinder,vsaid side wall of the cap having a forepart equal in outside diameter tothe diameter of the cylinder and having the keyhole of the front wallcontinuing through said forepart of the side wall; and interengagingmeans on the side wall of the cap and the cylinder at opposite sides ofthe keyhole to hold the portions of the side wall adjacent to thekeyhole against spreading apart during the application of the cap to thecylinder.

4. In combination with a lock cylinder for key controlled tumbler lockshaving a key slot opening to its cylindrical surface: a cap for thefront end of the lock, said cap being formed of sheet metal and having afront wall provided with a keyhole and a multiple diameter cylindricalside wall, the forepart of said side wall having an outside diameter nogreater than the diameter of the cylinder and the rear portion of theside wall having a close t on the cylinder, the side wall of saidforepart of the cap having the keyhole continuing therethrough; tangsstruck inwardly from the side wall of the forepart of the cap atopposite sides of the keyhole; and the adjacent forepart of the cylinderhaving recesses to receive said tangs; the interengaging portions of thetangs and recesses being so shaped that the cap is drawn about thecylinder during application thereof onto the cylinder.

5. In combination with a lock cylinder for key controlled tumbler lockshaving a key slot opening to its cylindrical surface: a cap for thefront end of the lock, said cap being formed of sheet metal and having afront wall provided with a keyhole and a multiple diameter cylindricalside wall, the forepart of said side wall having an outside diameter nogreater than the diameter of the cylinder and the rear portion of theside wall having a close t on the cylinder, the side wall of saidforepart of the cap having they keyhole continuing therethrough; tangsstruck inwardly from the side wall of the forepart of the cap atopposite sides of the keyhole; and the adjacent forepart of the cylinderhaving recesses to receive said tangs, said recesses having taperedwalls so inclined that during application of the cap onto the cylinder,the consequent engagement of the tangs with said inclined walls drawsthe cap about the cylinder to offset bursting stresses acting on thecap.

6. In a lock, the combination of: a support having a chamber to receivea lock casing and having a hole in its front wall; a bored lock casingdisposed in said chamber; a cylinder rotatable in the bore with itsfront end projecting into the hole in the support, said hole having adiameter substantially equal'to that of the cylinder, and the forepartof the cylinder which projects into the hole having a smaller diameter;a cap tted over the front end of the cylinder and having a iront wallprovided with a substantially diametrical keyhole which continues intothe side wall of the forepart of the cap, said cylinder having a keyslot in line with the keyhole of the cap and opening to the cylindricalsurface of the cylinder, the wall thickness of the orepart of the capbeing such that its outside diameter is substantially equal to that ofthe cylinder; the side wall of the cap having its inner rear partenlarged in diameter to fit the outside of the cylinder and having thejuncture of its two diameters engaging the shoulder formed by the innerlend of the hole in the support; and means for maintaining the capassembled with the cylinder.

7. In a lock: a bored casing having a counterbore at the mouth of itsbore; a cylinder rotatable in the bore with its forepart projectingtherefrom beyond the counterbore; the extreme forepart of the cylinderbeing reduced in diameter; a cap fitted over the forepart of thecylinder and having a front wall provided with a keyhole and acylindrical side wall of two diameters, the smaller of which ts thereduced forepart of the cylinder, said small diameter part of the sidewall having the keyhole continuing therethrough, the cylinder having akey slot in line with the keyhole; an annular flange on the inner largediameter end of the cap received in the counterbore of the casing; andmeans carried by the casing and projecting into the counterbore tooverlie said flange.

8. In a lock: a bored casing having a counterbore at the mouth of itsbore; a cylinder rotatable in the bore with its forepart projectingtherefrom beyond the counterbore; the extreme forepart of the cylinderbeing reduced in diameter; a cap tted over the forepart of the cylinderand having a front wall provided with a keyhole and a cylindrical sidewall of two diameters, the smaller of which ts the reduced forepart ofthe cylinder, said small diameter part o1 the side wall having thekeyhole continuing therethrough, the cylinder having a key slot in linewith the keyhole; an annular Iiange on the inn-er large diameter end ofthe cap received in the counterbore of the casing; means carried by thecasing and projecting into the counterbore to overlie said ilange; andcooperating interengageable means on the side wall of the cap and thecylinder for holding the cap against rotation on the cylinder and foroffsetting bursting stresses imposed on the cap during applicationthereof onto the cylinder.

EDWARD N. JACOBI.

